[SOLVED] How to format elapsedTime start at 00:00:00 instead of the default 07:00:00 in Swift

How to format elapsedTime start at 00:00:00 instead of the default 07:00:00 in Swift

I cannot find a way to have the stopwatch display start at 00:00:00 using QuartzCore. It always starts at 07:00:00.

Is there a way to format the start time to be 00:00:00? Code is below.

Thanks!!

Class:

import Foundation
import QuartzCore

class StopWatch: NSObject{

private var displayLink: CADisplayLink!
private let formatter = DateFormatter()

var callback: (() -> Void)?
var elapsedTime: CFTimeInterval!

override init() {
    super.init()
    self.displayLink = CADisplayLink(target: self, selector: #selector(tick(sender:)))
    displayLink.isPaused = true
    displayLink.add(to: RunLoop.main, forMode: RunLoopMode.commonModes)
    self.elapsedTime = 0.0
    formatter.dateFormat = "HH:mm:ss"
}
convenience init(withCallback callback: @escaping () -> Void) {
    self.init()
    self.callback = callback
}
deinit {
    displayLink.invalidate()
}

func tick(sender: CADisplayLink) {
    elapsedTime = elapsedTime + displayLink.duration
    callback?()
}


func elapsedTimeAsString() -> String {
    return formatter.string(from: Date(timeIntervalSinceReferenceDate:elapsedTime))
}

}

Solution

CORRECTED as mentioned in the comment below: As the commenter above mentioned, this was a timezone issue since I am located in GMT +7. I added the following code to solve the issue:

formatter.timeZone = TimeZone(abbreviation: "GMT")!